1
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Wang H, Bollepogu Raja KK, Yeung K, Morrison CA, Terrizzano A, Khodadadi-Jamayran A, Chen P, Jordan A, Fritsch C, Sprecher SG, Mardon G, Treisman JE. Synergistic activation by Glass and Pointed promotes neuronal identity in the Drosophila eye disc. Nat Commun 2024; 15:7091. [PMID: 39154080 PMCID: PMC11330500 DOI: 10.1038/s41467-024-51429-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 08/06/2024] [Indexed: 08/19/2024] Open
Abstract
The integration of extrinsic signaling with cell-intrinsic transcription factors can direct progenitor cells to differentiate into distinct cell fates. In the developing Drosophila eye, differentiation of photoreceptors R1-R7 requires EGFR signaling mediated by the transcription factor Pointed, and our single-cell RNA-Seq analysis shows that the same photoreceptors require the eye-specific transcription factor Glass. We find that ectopic expression of Glass and activation of EGFR signaling synergistically induce neuronal gene expression in the wing disc in a Pointed-dependent manner. Targeted DamID reveals that Glass and Pointed share many binding sites in the genome of developing photoreceptors. Comparison with transcriptomic data shows that Pointed and Glass induce photoreceptor differentiation through intermediate transcription factors, including the redundant homologs Scratch and Scrape, as well as directly activating neuronal effector genes. Our data reveal synergistic activation of a multi-layered transcriptional network as the mechanism by which EGFR signaling induces neuronal identity in Glass-expressing cells.
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Affiliation(s)
- Hongsu Wang
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY, USA
| | | | - Kelvin Yeung
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Carolyn A Morrison
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY, USA
- 10x Genomics, Pleasanton, CA, 94588, USA
| | - Antonia Terrizzano
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY, USA
- Biology of Centrosomes and Genetic Instability Team, Curie Institute, PSL Research University, CNRS, UMR144, 12 rue Lhomond, Paris, 75005, France
| | | | - Phoenix Chen
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY, USA
- Department of Biology, Boston University, Boston, MA, USA
| | - Ashley Jordan
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY, USA
| | - Cornelia Fritsch
- Department of Biology, Université de Fribourg, Fribourg, Switzerland
| | - Simon G Sprecher
- Department of Biology, Université de Fribourg, Fribourg, Switzerland
| | - Graeme Mardon
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jessica E Treisman
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY, USA.
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2
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Huang Y, Yu G, Yang Y. MIGGRI: A multi-instance graph neural network model for inferring gene regulatory networks for Drosophila from spatial expression images. PLoS Comput Biol 2023; 19:e1011623. [PMID: 37939200 PMCID: PMC10659162 DOI: 10.1371/journal.pcbi.1011623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 11/20/2023] [Accepted: 10/22/2023] [Indexed: 11/10/2023] Open
Abstract
Recent breakthrough in spatial transcriptomics has brought great opportunities for exploring gene regulatory networks (GRNs) from a brand-new perspective. Especially, the local expression patterns and spatio-temporal regulation mechanisms captured by spatial expression images allow more delicate delineation of the interplay between transcript factors and their target genes. However, the complexity and size of spatial image collections pose significant challenges to GRN inference using image-based methods. Extracting regulatory information from expression images is difficult due to the lack of supervision and the multi-instance nature of the problem, where a gene often corresponds to multiple images captured from different views. While graph models, particularly graph neural networks, have emerged as a promising method for leveraging underlying structure information from known GRNs, incorporating expression images into graphs is not straightforward. To address these challenges, we propose a two-stage approach, MIGGRI, for capturing comprehensive regulatory patterns from image collections for each gene and known interactions. Our approach involves a multi-instance graph neural network (GNN) model for GRN inference, which first extracts gene regulatory features from spatial expression images via contrastive learning, and then feeds them to a multi-instance GNN for semi-supervised learning. We apply our approach to a large set of Drosophila embryonic spatial gene expression images. MIGGRI achieves outstanding performance in the inference of GRNs for early eye development and mesoderm development of Drosophila, and shows robustness in the scenarios of missing image information. Additionally, we perform interpretable analysis on image reconstruction and functional subgraphs that may reveal potential pathways or coordinate regulations. By leveraging the power of graph neural networks and the information contained in spatial expression images, our approach has the potential to advance our understanding of gene regulation in complex biological systems.
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Affiliation(s)
- Yuyang Huang
- Department of Computer Science and Engineering, Shanghai Jiao Tong University, and Key Laboratory of Shanghai Education Commission for Intelligent Interaction and Cognitive Engineering, Shanghai, China
| | - Gufeng Yu
- Department of Computer Science and Engineering, Shanghai Jiao Tong University, and Key Laboratory of Shanghai Education Commission for Intelligent Interaction and Cognitive Engineering, Shanghai, China
| | - Yang Yang
- Department of Computer Science and Engineering, Shanghai Jiao Tong University, and Key Laboratory of Shanghai Education Commission for Intelligent Interaction and Cognitive Engineering, Shanghai, China
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3
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Baldenius M, Kautzmann S, Nanda S, Klämbt C. Signaling Pathways Controlling Axonal Wrapping in Drosophila. Cells 2023; 12:2553. [PMID: 37947631 PMCID: PMC10647682 DOI: 10.3390/cells12212553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023] Open
Abstract
The rapid transmission of action potentials is an important ability that enables efficient communication within the nervous system. Glial cells influence conduction velocity along axons by regulating the radial axonal diameter, providing electrical insulation as well as affecting the distribution of voltage-gated ion channels. Differentiation of these wrapping glial cells requires a complex set of neuron-glia interactions involving three basic mechanistic features. The glia must recognize the axon, grow around it, and eventually arrest its growth to form single or multiple axon wraps. This likely depends on the integration of numerous evolutionary conserved signaling and adhesion systems. Here, we summarize the mechanisms and underlying signaling pathways that control glial wrapping in Drosophila and compare those to the mechanisms that control glial differentiation in mammals. This analysis shows that Drosophila is a beneficial model to study the development of even complex structures like myelin.
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Affiliation(s)
| | | | | | - Christian Klämbt
- Institute for Neuro- and Behavioral Biology, Faculty of Biology, University of Münster, Röntgenstraße 16, D-48149 Münster, Germany; (M.B.)
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4
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Eberwein AE, Kulkarni SS, Rushton E, Broadie K. Glycosphingolipids are linked to elevated neurotransmission and neurodegeneration in a Drosophila model of Niemann Pick type C. Dis Model Mech 2023; 16:dmm050206. [PMID: 37815467 PMCID: PMC10581387 DOI: 10.1242/dmm.050206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023] Open
Abstract
The lipid storage disease Niemann Pick type C (NPC) causes neurodegeneration owing primarily to loss of NPC1. Here, we employed a Drosophila model to test links between glycosphingolipids, neurotransmission and neurodegeneration. We found that Npc1a nulls had elevated neurotransmission at the glutamatergic neuromuscular junction (NMJ), which was phenocopied in brainiac (brn) mutants, impairing mannosyl glucosylceramide (MacCer) glycosylation. Npc1a; brn double mutants had the same elevated synaptic transmission, suggesting that Npc1a and brn function within the same pathway. Glucosylceramide (GlcCer) synthase inhibition with miglustat prevented elevated neurotransmission in Npc1a and brn mutants, further suggesting epistasis. Synaptic MacCer did not accumulate in the NPC model, but GlcCer levels were increased, suggesting that GlcCer is responsible for the elevated synaptic transmission. Null Npc1a mutants had heightened neurodegeneration, but no significant motor neuron or glial cell death, indicating that dying cells are interneurons and that elevated neurotransmission precedes neurodegeneration. Glycosphingolipid synthesis mutants also had greatly heightened neurodegeneration, with similar neurodegeneration in Npc1a; brn double mutants, again suggesting that Npc1a and brn function in the same pathway. These findings indicate causal links between glycosphingolipid-dependent neurotransmission and neurodegeneration in this NPC disease model.
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Affiliation(s)
- Anna E. Eberwein
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Swarat S. Kulkarni
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Emma Rushton
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
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5
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Almazán A, Çevrim Ç, Musser JM, Averof M, Paris M. Crustacean leg regeneration restores complex microanatomy and cell diversity. SCIENCE ADVANCES 2022; 8:eabn9823. [PMID: 36001670 PMCID: PMC9401613 DOI: 10.1126/sciadv.abn9823] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Animals can regenerate complex organs, yet this process frequently results in imprecise replicas of the original structure. In the crustacean Parhyale, embryonic and regenerating legs differ in gene expression dynamics but produce apparently similar mature structures. We examine the fidelity of Parhyale leg regeneration using complementary approaches to investigate microanatomy, sensory function, cellular composition, and cell molecular profiles. We find that regeneration precisely replicates the complex microanatomy and spatial distribution of external sensory organs and restores their sensory function. Single-nuclei sequencing shows that regenerated and uninjured legs are indistinguishable in terms of cell-type composition and transcriptional profiles. This remarkable fidelity highlights the ability of organisms to achieve identical outcomes via distinct processes.
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Affiliation(s)
- Alba Almazán
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
| | - Çağrı Çevrim
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
| | - Jacob M. Musser
- European Molecular Biology Laboratory, Developmental Biology Unit, Meyerhofstrasse 1, Heidelberg 69117, Germany
| | - Michalis Averof
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
| | - Mathilde Paris
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
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6
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Tavares L, Grácio P, Ramos R, Traquete R, Relvas JB, Pereira PS. The Pebble/Rho1/Anillin pathway controls polyploidization and axonal wrapping activity in the glial cells of the Drosophila eye. Dev Biol 2021; 473:90-96. [PMID: 33581137 DOI: 10.1016/j.ydbio.2021.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 10/22/2022]
Abstract
During development glial cell are crucially important for the establishment of neuronal networks. Proliferation and migration of glial cells can be modulated by neurons, and in turn glial cells can differentiate to assume key roles such as axonal wrapping and targeting. To explore the roles of actin cytoskeletal rearrangements in glial cells, we studied the function of Rho1 in Drosophila developing visual system. We show that the Pebble (RhoGEF)/Rho1/Anillin pathway is required for glia proliferation and to prevent the formation of large polyploid perineurial glial cells, which can still migrate into the eye disc if generated. Surprisingly, this Rho1 pathway is not necessary to establish the total glial membrane area or for the differentiation of the polyploid perineurial cells. The resulting polyploid wrapping glial cells are able to initiate wrapping of axons in the basal eye disc, however the arrangement and density of glia nuclei and membrane processes in the optic stalk are altered and the ensheathing of the photoreceptor axonal fascicles is reduced.
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Affiliation(s)
- Lígia Tavares
- i3S - Instituto de Investigação e Inovação Em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal.
| | - Patrícia Grácio
- i3S - Instituto de Investigação e Inovação Em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - Raquel Ramos
- i3S - Instituto de Investigação e Inovação Em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - Rui Traquete
- i3S - Instituto de Investigação e Inovação Em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - João B Relvas
- i3S - Instituto de Investigação e Inovação Em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - Paulo S Pereira
- i3S - Instituto de Investigação e Inovação Em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal.
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7
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Tsao CK, Huang YF, Sun YH. Early lineage segregation of the retinal basal glia in the Drosophila eye disc. Sci Rep 2020; 10:18522. [PMID: 33116242 PMCID: PMC7595039 DOI: 10.1038/s41598-020-75581-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/16/2020] [Indexed: 11/09/2022] Open
Abstract
The retinal basal glia (RBG) is a group of glia that migrates from the optic stalk into the third instar larval eye disc while the photoreceptor cells (PR) are differentiating. The RBGs are grouped into three major classes based on molecular and morphological characteristics: surface glia (SG), wrapping glia (WG) and carpet glia (CG). The SGs migrate and divide. The WGs are postmitotic and wraps PR axons. The CGs have giant nucleus and extensive membrane extension that each covers half of the eye disc. In this study, we used lineage tracing methods to determine the lineage relationships among these glia subtypes and the temporal profile of the lineage decisions for RBG development. We found that the CG lineage segregated from the other RBG very early in the embryonic stage. It has been proposed that the SGs migrate under the CG membrane, which prevented SGs from contacting with the PR axons lying above the CG membrane. Upon passing the front of the CG membrane, which is slightly behind the morphogenetic furrow that marks the front of PR differentiation, the migrating SG contact the nascent PR axon, which in turn release FGF to induce SGs' differentiation into WG. Interestingly, we found that SGs are equally distributed apical and basal to the CG membrane, so that the apical SGs are not prevented from contacting PR axons by CG membrane. Clonal analysis reveals that the apical and basal RBG are derived from distinct lineages determined before they enter the eye disc. Moreover, the basal SG lack the competence to respond to FGFR signaling, preventing its differentiation into WG. Our findings suggest that this novel glia-to-glia differentiation is both dependent on early lineage decision and on a yet unidentified regulatory mechanism, which can provide spatiotemporal coordination of WG differentiation with the progressive differentiation of photoreceptor neurons.
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Affiliation(s)
- Chia-Kang Tsao
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Yu Fen Huang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,, 64 Marvin Lane, Piscataway, NJ, 08854, USA
| | - Y Henry Sun
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC. .,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.
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8
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Wrapping glia regulates neuronal signaling speed and precision in the peripheral nervous system of Drosophila. Nat Commun 2020; 11:4491. [PMID: 32901033 PMCID: PMC7479103 DOI: 10.1038/s41467-020-18291-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 08/11/2020] [Indexed: 02/06/2023] Open
Abstract
The functionality of the nervous system requires transmission of information along axons with high speed and precision. Conductance velocity depends on axonal diameter whereas signaling precision requires a block of electrical crosstalk between axons, known as ephaptic coupling. Here, we use the peripheral nervous system of Drosophila larvae to determine how glia regulates axonal properties. We show that wrapping glial differentiation depends on gap junctions and FGF-signaling. Abnormal glial differentiation affects axonal diameter and conductance velocity and causes mild behavioral phenotypes that can be rescued by a sphingosine-rich diet. Ablation of wrapping glia does not further impair axonal diameter and conductance velocity but causes a prominent locomotion phenotype that cannot be rescued by sphingosine. Moreover, optogenetically evoked locomotor patterns do not depend on conductance speed but require the presence of wrapping glial processes. In conclusion, our data indicate that wrapping glia modulates both speed and precision of neuronal signaling.
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9
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Bittern J, Pogodalla N, Ohm H, Brüser L, Kottmeier R, Schirmeier S, Klämbt C. Neuron-glia interaction in the Drosophila nervous system. Dev Neurobiol 2020; 81:438-452. [PMID: 32096904 DOI: 10.1002/dneu.22737] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/11/2020] [Accepted: 02/24/2020] [Indexed: 12/14/2022]
Abstract
Animals are able to move and react in manifold ways to external stimuli. Thus, environmental stimuli need to be detected, information must be processed, and, finally, an output decision must be transmitted to the musculature to get the animal moving. All these processes depend on the nervous system which comprises an intricate neuronal network and many glial cells. Glial cells have an equally important contribution in nervous system function as their neuronal counterpart. Manifold roles are attributed to glia ranging from controlling neuronal cell number and axonal pathfinding to regulation of synapse formation, function, and plasticity. Glial cells metabolically support neurons and contribute to the blood-brain barrier. All of the aforementioned aspects require extensive cell-cell interactions between neurons and glial cells. Not surprisingly, many of these processes are found in all phyla executed by evolutionarily conserved molecules. Here, we review the recent advance in understanding neuron-glia interaction in Drosophila melanogaster to suggest that work in simple model organisms will shed light on the function of mammalian glial cells, too.
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Affiliation(s)
- Jonas Bittern
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Nicole Pogodalla
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Henrike Ohm
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Lena Brüser
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Rita Kottmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Stefanie Schirmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Christian Klämbt
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
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10
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Ray M, Singh G, Lakhotia SC. Altered levels of hsromega lncRNAs further enhance Ras signaling during ectopically activated Ras induced R7 differentiation in Drosophila. Gene Expr Patterns 2019; 33:20-36. [DOI: 10.1016/j.gep.2019.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 05/07/2019] [Indexed: 12/15/2022]
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11
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Bageritz J, Willnow P, Valentini E, Leible S, Boutros M, Teleman AA. Gene expression atlas of a developing tissue by single cell expression correlation analysis. Nat Methods 2019; 16:750-756. [PMID: 31363221 PMCID: PMC6675608 DOI: 10.1038/s41592-019-0492-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 06/13/2019] [Indexed: 01/27/2023]
Abstract
The Drosophila wing disc has been a fundamental model system for the discovery of key signaling pathways and for our understanding of developmental processes. However, a complete map of gene expression in this tissue is lacking. To obtain a complete gene expression atlas in the wing disc, we employed single-cell sequencing (scRNA-seq) and developed a new method for analyzing scRNA-seq data based on gene expression correlations rather than cell mapping. This enables us to compute expression maps for all detected genes in the wing disc and to discover 824 genes with spatially restricted expression patterns. This approach identifies both known and new clusters of genes with similar expression patterns and functional relevance. As proof of concept, we characterize the previously unstudied gene CG5151 and show that it regulates Wnt signaling. This novel method will enable the leveraging of scRNA-seq data for generating expression atlases of undifferentiated tissues during development.
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Affiliation(s)
- Josephine Bageritz
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany
| | - Philipp Willnow
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany.,CellNetworks-Cluster of Excellence, Heidelberg University, Heidelberg, Germany
| | - Erica Valentini
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany
| | - Svenja Leible
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany
| | - Michael Boutros
- German Cancer Research Center (DKFZ), Heidelberg, Germany. .,Heidelberg University, Heidelberg, Germany.
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), Heidelberg, Germany. .,Heidelberg University, Heidelberg, Germany.
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12
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Reduced Expression of Sprouty1 Contributes to the Aberrant Proliferation and Impaired Apoptosis of Acute Myeloid Leukemia Cells. J Clin Med 2019; 8:jcm8070972. [PMID: 31277439 PMCID: PMC6678378 DOI: 10.3390/jcm8070972] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/02/2019] [Accepted: 07/02/2019] [Indexed: 12/17/2022] Open
Abstract
In most of the acute myeloid leukemia patients there is an aberrant tyrosine kinase activity. The prototype of Sprouty proteins was originally identified in Drosophila melanogaster as antagonists of Breathless, the mammalian ortholog of fibroblast growth factor receptor. Usually, SPRY family members are inhibitors of RAS signaling induced by tyrosine kinases receptors and they are implicated in negative feedback processes regulating several intracellular pathways. The present study aims to investigate the role of a member of the Sprouty family, Sprouty1, as a regulator of cell proliferation and growth in patients affected by acute myeloid leukemia. Sprouty1 mRNA and protein were both significantly down-regulated in acute myeloid leukemia cells compared to the normal counterpart, but they were restored when remission is achieved after chemotherapy. Ectopic expression of Sprouty1 revealed that it plays a key role in the proliferation and apoptotic defect that represent a landmark of the leukemic cells. Our study identified Sprouty1 as negative regulator involved in the aberrant signals of adult acute myeloid leukemia. Furthermore, we found a correlation between Sprouty1 and FoxO3a delocalization in acute myeloid leukemia (AML) patients at diagnosis, suggesting a multistep regulation of RAS signaling in human cancers.
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13
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Hans VR, Wendt TI, Patel AM, Patel MM, Perez L, Talbot DE, Jemc JC. Raw regulates glial population of the eye imaginal disc. Genesis 2018; 56:e23254. [DOI: 10.1002/dvg.23254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/25/2018] [Accepted: 09/29/2018] [Indexed: 01/25/2023]
Affiliation(s)
| | - Taylor I. Wendt
- Department of BiologyLoyola University Chicago Chicago Illinois
| | | | - Mit M. Patel
- Department of BiologyLoyola University Chicago Chicago Illinois
| | - Luselena Perez
- Department of BiologyLoyola University Chicago Chicago Illinois
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14
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Yildirim K, Petri J, Kottmeier R, Klämbt C. Drosophila glia: Few cell types and many conserved functions. Glia 2018; 67:5-26. [DOI: 10.1002/glia.23459] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/25/2018] [Accepted: 05/04/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Kerem Yildirim
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Johanna Petri
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Rita Kottmeier
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Christian Klämbt
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
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15
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Zülbahar S, Sieglitz F, Kottmeier R, Altenhein B, Rumpf S, Klämbt C. Differential expression of Öbek controls ploidy in the Drosophila blood-brain barrier. Development 2018; 145:dev.164111. [PMID: 30002129 DOI: 10.1242/dev.164111] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 07/03/2018] [Indexed: 12/13/2022]
Abstract
During development, tissue growth is mediated by either cell proliferation or cell growth, coupled with polyploidy. Both strategies are employed by the cell types that make up the Drosophila blood-brain barrier. During larval growth, the perineurial glia proliferate, whereas the subperineurial glia expand enormously and become polyploid. Here, we show that the level of ploidy in the subperineurial glia is controlled by the N-terminal asparagine amidohydrolase homolog Öbek, and high Öbek levels are required to limit replication. In contrast, perineurial glia express moderate levels of Öbek, and increased Öbek expression blocks their proliferation. Interestingly, other dividing cells are not affected by alteration of Öbek expression. In glia, Öbek counteracts fibroblast growth factor and Hippo signaling to differentially affect cell growth and number. We propose a mechanism by which growth signals are integrated differentially in a glia-specific manner through different levels of Öbek protein to adjust cell proliferation versus endoreplication in the blood-brain barrier.
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Affiliation(s)
- Selen Zülbahar
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Florian Sieglitz
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Rita Kottmeier
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Benjamin Altenhein
- Institute of Zoology, University of Cologne, Zülpicher Straße 47b, 50674 Cologne, Germany
| | - Sebastian Rumpf
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Christian Klämbt
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
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16
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Torres-Oliva M, Schneider J, Wiegleb G, Kaufholz F, Posnien N. Dynamic genome wide expression profiling of Drosophila head development reveals a novel role of Hunchback in retinal glia cell development and blood-brain barrier integrity. PLoS Genet 2018; 14:e1007180. [PMID: 29360820 PMCID: PMC5796731 DOI: 10.1371/journal.pgen.1007180] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 02/02/2018] [Accepted: 01/01/2018] [Indexed: 01/01/2023] Open
Abstract
Drosophila melanogaster head development represents a valuable process to study the developmental control of various organs, such as the antennae, the dorsal ocelli and the compound eyes from a common precursor, the eye-antennal imaginal disc. While the gene regulatory network underlying compound eye development has been extensively studied, the key transcription factors regulating the formation of other head structures from the same imaginal disc are largely unknown. We obtained the developmental transcriptome of the eye-antennal discs covering late patterning processes at the late 2nd larval instar stage to the onset and progression of differentiation at the end of larval development. We revealed the expression profiles of all genes expressed during eye-antennal disc development and we determined temporally co-expressed genes by hierarchical clustering. Since co-expressed genes may be regulated by common transcriptional regulators, we combined our transcriptome dataset with publicly available ChIP-seq data to identify central transcription factors that co-regulate genes during head development. Besides the identification of already known and well-described transcription factors, we show that the transcription factor Hunchback (Hb) regulates a significant number of genes that are expressed during late differentiation stages. We confirm that hb is expressed in two polyploid subperineurial glia cells (carpet cells) and a thorough functional analysis shows that loss of Hb function results in a loss of carpet cells in the eye-antennal disc. Additionally, we provide for the first time functional data indicating that carpet cells are an integral part of the blood-brain barrier. Eventually, we combined our expression data with a de novo Hb motif search to reveal stage specific putative target genes of which we find a significant number indeed expressed in carpet cells. The development of different cell types must be tightly coordinated, and the eye-antennal imaginal discs of Drosophila melanogaster represent an excellent model to study the molecular mechanisms underlying this coordination. These imaginal discs contain the anlagen of nearly all adult head structures, such as the antennae, the head cuticle, the ocelli and the compound eyes. While large scale screens have been performed to unravel the gene regulatory network underlying compound eye development, a comprehensive understanding of genome wide expression dynamics throughout head development is still missing to date. We studied the genome wide gene expression dynamics during eye-antennal disc development in D. melanogaster to identify new central regulators of the underlying gene regulatory network. Expression based gene clustering and transcription factor motif enrichment analyses revealed a central regulatory role of the transcription factor Hunchback (Hb). We confirmed that hb is expressed in two polyploid retinal subperineurial glia cells (carpet cells). Our functional analysis shows that Hb is necessary for carpet cell development and we show for the first time that the carpet cells are an integral part of the blood-brain barrier.
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Affiliation(s)
- Montserrat Torres-Oliva
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Julia Schneider
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Gordon Wiegleb
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Felix Kaufholz
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Nico Posnien
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
- * E-mail:
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17
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Sasse S, Klämbt C. Repulsive Epithelial Cues Direct Glial Migration along the Nerve. Dev Cell 2017; 39:696-707. [PMID: 27997826 DOI: 10.1016/j.devcel.2016.11.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 10/14/2016] [Accepted: 11/19/2016] [Indexed: 11/29/2022]
Abstract
Most glial cells show pronounced migratory abilities and generally follow axonal trajectories to reach their final destination. However, the molecular cues controlling their directional migration are largely unknown. To address this, we established glial migration onto the developing Drosophila leg imaginal disc as a model. Here, CNS-derived glial cells move along nerves containing motoaxons and sensory axons. Along their path, glial cells encounter at least three choice points where directional decisions are needed. Subsequent genetic analyses allowed uncovering mechanisms that escaped previous studies. Most strikingly, we found that glial cells require the expression of the repulsive guidance receptors PlexinA/B and Robo2 to prevent breaking away from the nerve. Interestingly, the repulsive ligands are presented by the underlying leg imaginal disc epithelium, which appears to push glial cells toward the axon fascicle. In conclusion, nerve formation not only requires neuron-glia interaction but also depends on glial-epithelial communication.
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Affiliation(s)
- Sofia Sasse
- Institut für Neuro- und Verhaltensbiologie, Badestraße 9, 48149 Münster, Germany
| | - Christian Klämbt
- Institut für Neuro- und Verhaltensbiologie, Badestraße 9, 48149 Münster, Germany.
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18
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Charlton-Perkins MA, Sendler ED, Buschbeck EK, Cook TA. Multifunctional glial support by Semper cells in the Drosophila retina. PLoS Genet 2017; 13:e1006782. [PMID: 28562601 PMCID: PMC5470715 DOI: 10.1371/journal.pgen.1006782] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 06/14/2017] [Accepted: 04/26/2017] [Indexed: 11/19/2022] Open
Abstract
Glial cells play structural and functional roles central to the formation, activity and integrity of neurons throughout the nervous system. In the retina of vertebrates, the high energetic demand of photoreceptors is sustained in part by Müller glia, an intrinsic, atypical radial glia with features common to many glial subtypes. Accessory and support glial cells also exist in invertebrates, but which cells play this function in the insect retina is largely undefined. Using cell-restricted transcriptome analysis, here we show that the ommatidial cone cells (aka Semper cells) in the Drosophila compound eye are enriched for glial regulators and effectors, including signature characteristics of the vertebrate visual system. In addition, cone cell-targeted gene knockdowns demonstrate that such glia-associated factors are required to support the structural and functional integrity of neighboring photoreceptors. Specifically, we show that distinct support functions (neuronal activity, structural integrity and sustained neurotransmission) can be genetically separated in cone cells by down-regulating transcription factors associated with vertebrate gliogenesis (pros/Prox1, Pax2/5/8, and Oli/Olig1,2, respectively). Further, we find that specific factors critical for glial function in other species are also critical in cone cells to support Drosophila photoreceptor activity. These include ion-transport proteins (Na/K+-ATPase, Eaat1, and Kir4.1-related channels) and metabolic homeostatic factors (dLDH and Glut1). These data define genetically distinct glial signatures in cone/Semper cells that regulate their structural, functional and homeostatic interactions with photoreceptor neurons in the compound eye of Drosophila. In addition to providing a new high-throughput model to study neuron-glia interactions, the fly eye will further help elucidate glial conserved "support networks" between invertebrates and vertebrates. Glia are the caretakers of the nervous system. Like their neighboring neurons, different glial subtypes exist that share many overlapping functions. Despite our recognition of glia as a key component of the brain, the genetic networks that mediate their neuroprotective functions remain relatively poorly understood. Here, using the genetic model Drosophila melanogaster, we identify a new glial cell type in one of the most active tissues in the nervous system—the retina. These cells, called ommatidial cone cells (or Semper cells), were previously recognized for their role in lens formation. Using cell-specific molecular genetic approaches, we demonstrate that cone cells (CCs) also share molecular, functional, and genetic features with both vertebrate and invertebrate glia to prevent light-induced retinal degeneration and provide structural and physiological support for photoreceptors. Further, we demonstrate that three factors associated with gliogenesis in vertebrates—prospero/Prox1, Pax2, and Oli/Olig1,2—control genetically distinct aspects of these support functions. CCs also share molecular and functional features with the three main glial types in the mammalian visual system: Müller glia, astrocytes, and oligodendrocytes. Combined, these studies provide insight into potentially deeply conserved aspects of glial functions in the visual system and introduce a high-throughput system to genetically dissect essential neuroprotective mechanisms.
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Affiliation(s)
- Mark A. Charlton-Perkins
- Department of Pediatrics, Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Edward D. Sendler
- Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Elke K. Buschbeck
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Tiffany A. Cook
- Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
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19
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Abstract
Fibroblast growth factors (FGFs) and their receptors (FGFRs) regulate numerous cellular processes. Deregulation of FGFR signalling is observed in a subset of many cancers, making activated FGFRs a highly promising potential therapeutic target supported by multiple preclinical studies. However, early-phase clinical trials have produced mixed results with FGFR-targeted cancer therapies, revealing substantial complexity to targeting aberrant FGFR signalling. In this Review, we discuss the increasing understanding of the differences between diverse mechanisms of oncogenic activation of FGFR, and the factors that determine response and resistance to FGFR targeting.
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Affiliation(s)
- Irina S Babina
- Breast Cancer Now Research Centre, Institute of Cancer Research, London SW3 6JB, UK
| | - Nicholas C Turner
- Breast Cancer Now Research Centre, Institute of Cancer Research, London SW3 6JB, UK
- Breast Unit, The Royal Marsden Hospital, Fulham Road, London SW3 6JJ, UK
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20
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Abstract
Cells respond to changes in their environment, to developmental cues, and to pathogen aggression through the action of a complex network of proteins. These networks can be decomposed into a multitude of signaling pathways that relay signals from the microenvironment to the cellular components involved in eliciting a specific response. Perturbations in these signaling processes are at the root of multiple pathologies, the most notable of these being cancer. The study of receptor tyrosine kinase (RTK) signaling led to the first description of a mechanism whereby an extracellular signal is transmitted to the nucleus to induce a transcriptional response. Genetic studies conducted in drosophila and nematodes have provided key elements to this puzzle. Here, we briefly discuss the somewhat lesser known contribution of these multicellular organisms to our understanding of what has come to be known as the prototype of signaling pathways. We also discuss the ostensibly much larger network of regulators that has emerged from recent functional genomic investigations of RTK/RAS/ERK signaling.
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Affiliation(s)
- Dariel Ashton-Beaucage
- Institute for Research in Immunology and Cancer, Laboratory of Intracellular Signaling, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC, Canada, H3C 3J7
| | - Marc Therrien
- Institute for Research in Immunology and Cancer, Laboratory of Intracellular Signaling, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC, Canada, H3C 3J7.
- Département de Pathologie et de Biologie Cellulaire, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC, Canada, H3C 3J7.
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21
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Neuert H, Yuva-Aydemir Y, Silies M, Klämbt C. Different modes of APC/C activation control growth and neuron-glia interaction in the developing Drosophila eye. Development 2017; 144:4673-4683. [DOI: 10.1242/dev.152694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/23/2017] [Indexed: 12/30/2022]
Abstract
The development of the nervous system requires tight control of cell division, fate specification and migration. The anaphase promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that affects different steps of cell cycle progression, as well as having postmitotic functions in nervous system development. It can therefore link different developmental stages in one tissue. The two adaptor proteins Fizzy/Cdc20 and Fizzy-Related/Cdh1 confer APC/C substrate specificity. Here we show that two distinct modes of APC/C function act during Drosophila eye development. Fizzy/Cdc20 controls the early growth of the eye disc anlage and the concomitant entry of glial cells onto the disc. In contrast, fzr/cdh1 acts during neuronal patterning and photoreceptor axon growth, and subsequently affects neuron-glia interaction. To further address the postmitotic role of Fzr/Cdh1 in controlling neuron-glia interaction, we identified a series of novel APC/C candidate substrates. Four of our candidate genes are required for fzr/cdh1 dependent neuron-glia interaction, including the dynein light chain Dlc90F. Taken together, our data show how different modes of APC/C activation can couple early growth and neuron-glia interaction during eye disc development.
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Affiliation(s)
- Helen Neuert
- Institut für Neurobiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
- Present address: Department of Cellular and Physiological Sciences, Life Sciences Centre, 2350 Health Sciences Mall, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Yeliz Yuva-Aydemir
- Institut für Neurobiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
- Present address: Department of Neurology, UMASS Medical School, Worcester, MA 01605, USA
| | - Marion Silies
- Institut für Neurobiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
- European Neuroscience Institute, University Medical Center Goettingen, Grisebachstr. 5, 37077 Göttingen, Germany
| | - Christian Klämbt
- Institut für Neurobiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
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22
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Carbone MA, Yamamoto A, Huang W, Lyman RA, Meadors TB, Yamamoto R, Anholt RRH, Mackay TFC. Genetic architecture of natural variation in visual senescence in Drosophila. Proc Natl Acad Sci U S A 2016; 113:E6620-E6629. [PMID: 27791033 PMCID: PMC5087026 DOI: 10.1073/pnas.1613833113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Senescence, i.e., functional decline with age, is a major determinant of health span in a rapidly aging population, but the genetic basis of interindividual variation in senescence remains largely unknown. Visual decline and age-related eye disorders are common manifestations of senescence, but disentangling age-dependent visual decline in human populations is challenging due to inability to control genetic background and variation in histories of environmental exposures. We assessed the genetic basis of natural variation in visual senescence by measuring age-dependent decline in phototaxis using Drosophila melanogaster as a genetic model system. We quantified phototaxis at 1, 2, and 4 wk of age in the sequenced, inbred lines of the Drosophila melanogaster Genetic Reference Panel (DGRP) and found an average decline in phototaxis with age. We observed significant genetic variation for phototaxis at each age and significant genetic variation in senescence of phototaxis that is only partly correlated with phototaxis. Genome-wide association analyses in the DGRP and a DGRP-derived outbred, advanced intercross population identified candidate genes and genetic networks associated with eye and nervous system development and function, including seven genes with human orthologs previously associated with eye diseases. Ninety percent of candidate genes were functionally validated with targeted RNAi-mediated suppression of gene expression. Absence of candidate genes previously implicated with longevity indicates physiological systems may undergo senescence independent of organismal life span. Furthermore, we show that genes that shape early developmental processes also contribute to senescence, demonstrating that senescence is part of a genetic continuum that acts throughout the life span.
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Affiliation(s)
- Mary Anna Carbone
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695; W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695; Program in Genetics, North Carolina State University, Raleigh, NC 27695
| | - Akihiko Yamamoto
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695; W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695; Program in Genetics, North Carolina State University, Raleigh, NC 27695
| | - Wen Huang
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695; W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695; Program in Genetics, North Carolina State University, Raleigh, NC 27695; Initiative in Biological Complexity, North Carolina State University, Raleigh, NC 27695
| | - Rachel A Lyman
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695
| | - Tess Brune Meadors
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695
| | - Ryoan Yamamoto
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695
| | - Robert R H Anholt
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695; W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695; Program in Genetics, North Carolina State University, Raleigh, NC 27695; Initiative in Biological Complexity, North Carolina State University, Raleigh, NC 27695
| | - Trudy F C Mackay
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695; W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695; Program in Genetics, North Carolina State University, Raleigh, NC 27695; Initiative in Biological Complexity, North Carolina State University, Raleigh, NC 27695
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23
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Identification of novel direct targets of Drosophila Sine oculis and Eyes absent by integration of genome-wide data sets. Dev Biol 2016; 415:157-167. [PMID: 27178668 DOI: 10.1016/j.ydbio.2016.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/06/2016] [Accepted: 05/07/2016] [Indexed: 12/12/2022]
Abstract
Drosophila eye development is a complex process that involves many transcription factors (TFs) and interactions with their cofactors and targets. The TF Sine oculis (So) and its cofactor Eyes absent (Eya) are highly conserved and are both necessary and sufficient for eye development. Despite their many important roles during development, the direct targets of So are still largely unknown. Therefore the So-dependent regulatory network governing eye determination and differentiation is poorly understood. In this study, we intersected gene expression profiles of so or eya mutant eye tissue prepared from three different developmental stages and identified 1731 differentially expressed genes across the Drosophila genome. A combination of co-expression analyses and motif discovery identified a set of twelve putative direct So targets, including three known and nine novel targets. We also used our previous So ChIP-seq data to assess motif predictions for So and identified a canonical So binding motif. Finally, we performed in vivo enhancer reporter assays to test predicted enhancers from six candidate target genes and find that at least one enhancer from each gene is expressed in the developing eye disc and that their expression patterns overlap with that of So. We furthermore confirmed that the expression level of predicted direct So targets, for which antibodies are available, are reduced in so or eya post-mitotic knockout eye discs. In summary, we expand the set of putative So targets and show for the first time that the combined use of expression profiling of so with its cofactor eya is an effective method to identify novel So targets. Moreover, since So is highly conserved throughout the metazoa, our results provide the basis for future functional studies in a wide variety of organisms.
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24
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Altenhein B, Cattenoz PB, Giangrande A. The early life of a fly glial cell. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015. [DOI: 10.1002/wdev.200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | | | - Angela Giangrande
- Department of Functional Genomics and Cancer; IGBMC; Illkirch France
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25
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Bauke AC, Sasse S, Matzat T, Klämbt C. A transcriptional network controlling glial development in the Drosophila visual system. Development 2015; 142:2184-93. [DOI: 10.1242/dev.119750] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 04/28/2015] [Indexed: 01/07/2023]
Abstract
In the nervous system, glial cells need to be specified from a set of progenitor cells. In the developing Drosophila eye, perineurial glia proliferate and differentiate as wrapping glia in response to a neuronal signal conveyed by the FGF receptor pathway. To unravel the underlying transcriptional network we silenced all genes encoding predicted DNA-binding proteins in glial cells using RNAi. Dref and other factors of the TATA box-binding protein-related factor 2 (TRF2) complex were previously predicted to be involved in cellular metabolism and cell growth. Silencing of these genes impaired early glia proliferation and subsequent differentiation. Dref controls proliferation via activation of the Pdm3 transcription factor, whereas glial differentiation is regulated via Dref and the homeodomain protein Cut. Cut expression is controlled independently of Dref by FGF receptor activity. Loss- and gain-of-function studies show that Cut is required for glial differentiation and is sufficient to instruct the formation of membrane protrusions, a hallmark of wrapping glial morphology. Our work discloses a network of transcriptional regulators controlling the progression of a naïve perineurial glia towards the fully differentiated wrapping glia.
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Affiliation(s)
- Ann-Christin Bauke
- Institute of Neurobiology, University of Münster, Münster 48149, Germany
| | - Sofia Sasse
- Institute of Neurobiology, University of Münster, Münster 48149, Germany
| | - Till Matzat
- Institute of Neurobiology, University of Münster, Münster 48149, Germany
| | - Christian Klämbt
- Institute of Neurobiology, University of Münster, Münster 48149, Germany
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26
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Abstract
Sprouty proteins are evolutionarily conserved modulators of MAPK/ERK pathway. Through interacting with an increasing number of effectors, mediators, and regulators with ultimate influence on multiple targets within or beyond ERK, Sprouty orchestrates a complex, multilayered regulatory system and mediates a crosstalk among different signaling pathways for a coordinated cellular response. As such, Sprouty has been implicated in various developmental and physiological processes. Evidence shows that ERK is aberrantly activated in malignant conditions. Accordingly, Sprouty deregulation has been reported in different cancer types and shown to impact cancer development, progression, and metastasis. In this article, we have tried to provide an overview of the current knowledge about the Sprouty physiology and its regulatory functions in health, as well as an updated review of the Sprouty status in cancer. Putative implications of Sprouty in cancer biology, their clinical relevance, and their proposed applications are also revisited. As a developing story, however, role of Sprouty in cancer remains to be further elucidated.
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Affiliation(s)
- Samar Masoumi-Moghaddam
- UNSW Department of Surgery, University of New South Wales, St George Hospital, Kogarah, Sydney, NSW, 2217, Australia,
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27
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Huang Y, Ng FS, Jackson FR. Comparison of larval and adult Drosophila astrocytes reveals stage-specific gene expression profiles. G3 (BETHESDA, MD.) 2015; 5:551-8. [PMID: 25653313 PMCID: PMC4390571 DOI: 10.1534/g3.114.016162] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/02/2015] [Indexed: 01/05/2023]
Abstract
The analysis of adult astrocyte glial cells has revealed a remarkable heterogeneity with regard to morphology, molecular signature, and physiology. A key question in glial biology is how such heterogeneity arises during brain development. One approach to this question is to identify genes with differential astrocyte expression during development; certain genes expressed later in neural development may contribute to astrocyte differentiation. We have utilized the Drosophila model and Translating Ribosome Affinity Purification (TRAP)-RNA-seq methods to derive the genome-wide expression profile of Drosophila larval astrocyte-like cells (hereafter referred to as astrocytes) for the first time. These studies identified hundreds of larval astrocyte-enriched genes that encode proteins important for metabolism, energy production, and protein synthesis, consistent with the known role of astrocytes in the metabolic support of neurons. Comparison of the larval profile with that observed for adults has identified genes with astrocyte-enriched expression specific to adulthood. These include genes important for metabolism and energy production, translation, chromatin modification, protein glycosylation, neuropeptide signaling, immune responses, vesicle-mediated trafficking or secretion, and the regulation of behavior. Among these functional classes, the expression of genes important for chromatin modification and vesicle-mediated trafficking or secretion is overrepresented in adult astrocytes based on Gene Ontology analysis. Certain genes with selective adult enrichment may mediate functions specific to this stage or may be important for the differentiation or maintenance of adult astrocytes, with the latter perhaps contributing to population heterogeneity.
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Affiliation(s)
- Yanmei Huang
- Department of Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Fanny S Ng
- Department of Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - F Rob Jackson
- Department of Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts 02111
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28
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Cattenoz PB, Giangrande A. New insights in the clockwork mechanism regulating lineage specification: Lessons from the Drosophila nervous system. Dev Dyn 2014; 244:332-41. [PMID: 25399853 DOI: 10.1002/dvdy.24228] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/06/2014] [Accepted: 11/07/2014] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Powerful transcription factors called fate determinants induce robust differentiation programs in multipotent cells and trigger lineage specification. These factors guarantee the differentiation of specific tissues/organs/cells at the right place and the right moment to form a fully functional organism. Fate determinants are activated by temporal, positional, epigenetic, and post-transcriptional cues, hence integrating complex and dynamic developmental networks. In turn, they activate specific transcriptional/epigenetic programs that secure novel molecular landscapes. RESULTS In this review, we use the Drosophila Gcm glial determinant as a model to discuss the mechanisms that allow lineage specification in the nervous system. The dynamic regulation of Gcm via interlocked loops has recently emerged as a key event in the establishment of stable identity. Gcm induces gliogenesis while triggering its own extinction, thus preventing the appearance of metastable states and neoplastic processes. CONCLUSIONS Using simple animal models that allow in vivo manipulations provides a key tool to disentangle the complex regulation of cell fate determinants.
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Affiliation(s)
- Pierre B Cattenoz
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France; Centre National de la Recherche Scientifique, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, Illkirch, France; Université de Strasbourg, Illkirch, France
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29
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Abstract
Signaling in development is not always on or off; often, distinct intensity and duration of signaling leads to distinct outcomes. This is true for receptor tyrosine kinase (RTK) signaling in many contexts, where negative feedback often plays a role. Although such negative feedback might reduce or even turn off signaling output over time, continued signaling is often maintained for proper cell fate specification. In this issue, Sieglitz et al. identify a positive regulator of Ras-mediated RTK signaling that they name Rau. Rau is necessary to achieve specific signaling intensity for the differentiation of photoreceptors and of glia that wrap axons in the developing Drosophila eye disc. Both the negative regulator Sprouty and Rau influence signaling through the guanosine triphosphatase Ras; specifically, Rau forms a positive feedback loop important for counteracting the Sprouty negative feedback loop.
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Affiliation(s)
- Michael Perry
- 1Center for Developmental Genetics, New York University (NYU), New York, NY 10003, USA
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